First-order Raman spectra of double perovskites AB′1/2B'{1/2}B''{1/2}O3

First principles computations of Raman intensities were performed for perovskite-family compound CaAl$_{1/2}$Nb$_{1/2}$O$_3$ (CAN). This compound features 1:1 (NaCl-type) ordering of Al and Nb superimposed onto the $b^-b^-c+$ octahedral tilting. Raman tensor for CAN was computed using the package for first-principles computations ABINIT (URL \underline {http://www.abinit.org}). Computations performed for both untilted cubic ($Fm\bar{3}m$) and tilted monoclinic ($P2_1/n$) CAN structures showed that the strongest Raman lines are associated with the ordering of Al and Nb. The computed spectrum agreed qualitatively with the experimental data measured on powder (CAN is available in polycrystalline form only). The effect of cation disorder on the Raman intensities was considered using phenomenological theory of light scattering in the vicinity of a phase transition. We suggest that, for certain modes, the corresponding Raman intensities depend primarily on the average long range order while, for other modes, the intensities are determined by fluctuations of the order parameter.Comment: 4 figures, submitte

A real time spectroscopic analysis of the eye tissue of animals in the Antarctic region using a portable Raman spectrophotometer

第2回極域科学シンポジウム/第33回極域生物シンポジウム 11月17日（木） 統計数理研究所 3階リフレッシュフロ

Water liquid structure as studied by Raman and hyper-Raman spectroscopy

Despite extensive studies over the years, anomalous behavior of water as a liquid still remains a mystery. We challenge this mystery by state-of-theart Raman and hyper-Raman spectroscopy.Published versio